Could bees be an early warning sign of human impact on our ecosystems? When the news broke in recent years that global honeybee populations were declining at an alarming rate, scientists took notice. The role bees play in nature simply cannot be overstated. A world without them would be unrecognizable since they pollinate many of the food crops we depend on. As the collapse of bee colonies becomes more and severe, scientists and beekeepers work to find the cause.